Slide-valve for steam-engines



(No Model.)

' J. SMITH. I

SLIDEVALVE FOR STEAM ENGINES. I

No. 275,725. Patented Apr.10,1883.

Wmsed 61 6). 6 m/ UNITED STATES PATENT OFFICE.

JESSE M; SMITH, OF DETROIT, MICHIGAN.

SLIDE-VALVE FOR STEAM-ENGINES.

SPECIFICATION formingpart of Letters Patent No. 275,725, dated April 10, 1883.

Application filed January 23, 1883. (No model.)

To all whom t't may concern Be it known that I, JESSE M. SMITH, of Detroit, in the county of Wayne and State of Michigan, have invented a new and useful Improvement in Out-Off Slide-Valves for Steam- Engines, which improvement is fully set forth in the following specification.

This invention has for its object to render small the travel of the slide-valve, to secure a large and free exhaust to limit the travel of the cut-0E, and to combine these advantages in one apparatus.

It consist, first, in a multiported steam-valve having a series of enlarged exhaust-ports and a series of smaller steam-ports, in combination with a cylinder having a series of ports corresponding in size with the said exhaust-ports; and, secondly, in a multiported valve having a series of exhaust-passages extending from the ports at the 'face of the valve to the side and bottom of said valve, and provided with a series of steam-ports in the walls of the exhaust-passages.

It further comprises certain particular constructions and combinations of parts, as here inafter set forth.

In the accompanying drawings, which form a part of this specification, Figure 1 is a horizontal section of an engine cylinder and valve constructed in accordance with the invention; Fig. 2, a view showing the valve partly in face view and partly in vertical longitudinal section; and Figs. 3 and 4, vertical cross-sections, showing the one the cylinder taking steamand the other the same exhausting.

A is the cylinder; B, thepiston; O, the slidevalve, and D the cut-off valve. E is the steamchest.

At each end of the cylinder A are a series of ports, a. Three ports are shown; but the number may be less or more. They communicate with a channel, 1", at the circumference of the cylinder-head, which channel extends to the bottom of the cylinder. The slide-valve G is in two parts, connected by the bars b. Each part has its interior divided by webs or partitions c. In these webs or partitions c are formed the steam-ports d, in number corresponding with the cylinder-ports. In the face of the valve are formed the exhaust-ports e, which communicate with the exhaust-passages f between the webs or partitions a.

extend or may extend only part way across the valve, and are or may be made rather narrower than the exhaust-ports c, with which the cylinder-ports correspond in size.

. In order to drain the cylinder of condensed water, the bottoms of the cylinder-ports and of the channels '2" are inclined downward. (See Figs. 3 and 4.) The back of the valve is inclined at t. This contracts the exhaust-passagesf at the top of the valve; but since only a small amount of steam passes through them the contraction does not interfere with the free flow of the exhaust-steam. It diminishes the weight of the valve by removing some of the material. The inclinepreferably extends about two-thirds the width of the valve, and in this upper part of the valve the steam-ports d are" formed. The said ports 61 being formed in the webs or partitions c, the latter must have at the top suflicient thickness to contain them. Toward the bottom of the valve the thickness of the partitions is diminished; or the latter are altogether discontinued, thus increasing the area of the exhaust-passages.

The cut-0E valve D comprises two plates, k, connected by the rod l, to which they are attached. Each plate has openings m, which register with the steam-ports d for a suitable part of the stroke. Itis mounted upon the inclined part i of the back ofthe valve. The number of steam-ports in the valve diminishes the travel as well of the cut-off valve as of the slidevalve. As there may be as many ports at as desirable, they may be very narrow as compared with the travel of the valve, and the cut off made as quick as desired. The valves may .be operatedby anysuitable gear. The cut-off plates being small and with small travel, they may be driven by an eccentric loose on the shaft, and commanded by a governor mounted on thesame shaft, the resistance of the cut-off valve being light compared with the force of IOC the governor. The main valve is commanded I by an eccentric fixed on the shaft, which assures constant lead, exhaust opening, and compression, while the cut-off may be varied by turning the cut-off eccentric on the shaft more or less, according to the work to he done by the piston. The valve is therefore specially adapted to automatic engines.

Modifications maybe made in the details of construction without departing from the spirit of the invention, and parts thereof maybe sep arately used, if desired. For example, avalve otherwise constructed as described could be made with the exhaust-outlet in the middle, between the two parts of the slide-valve, the said outlet communicating with the exhaustpassages of both ends; but in this case the advantages of having the exhaust-outlet opposite the cylinder-ports would be lost; also, a slide-valve with one exhaust-port and one steam-port could be made as described, except, of course, as to the multiplicity ofports, and of course, also, the advantages of such m ultiplicity would be lost. The slide-valve could be used without a cut-oft valve. Many other changes could be made, and the invention still be employed in whole or in part.

Having now fully described my said invention and the manner of carrying the same into effect, what I claim is 1. Amultiported steanrvalve having a series of enlarged exhaust-ports and aseries of smaller steam-ports,in combination with a cylinder having a series of ports corresponding in size with the said exhaust-ports, substantially as described.

2. A multiported slide-valve having its interior divided by one or more webs or partitions into exhaust-passages leading from the face of the valve to the side or bottom thereof, and provided with a series of exhaust-ports opening into said passages, and a series of steam-ports in said partitions or the walls of said passages, substantially as described.

3. In a steam-engine, the cylinder having ports extending to the middle thereof, and an upright steam-chest placed at the side of the cylinder, and having an exhaust-outlet in the bottom thereof, opposite the cylinder-ports, in combination with an upright slide-valve having exhaust-passages extending from the face of said valve to the bottom thereof, substantially as described.

4. In a multiported valve, a series of exhaustpassages extending from the face of the valve to the side or bottom thereof, and communicating with a common exhaust-outlet, substantially as described. 7

5. A multiported slide-valve having a series of steam-ports and a series of exhaust-ports, with exhaust-passages extending from said exhaust-ports to the side or bottom of the valve, in combination with a cut-offvalve carried on the back of the valve for controlling theadmis sion of steam to said steam-ports, substantially as described.

6. A multiported slidc-valvehaving exhaust ports in the face, and the exhaust-outlet at the side or bottom thereof, substantially as described.

7. A multiported slide-valve having steamports extending part way and exhaust-ports extending entirely or substantially across the same,and provided with exhaust-passages com municating with said exhaust-ports,said steamports being in the upper part of the valve, and said passages being larger at the bottom than at the top, substantially as described.

In testimony whereofI have signed this specification in the presence of two subscribing witnesses.

JESSE 'M. SMITH.

Witnesses:

PHILIP MAURO, G. J. HEDRICK. 

